aop里获取mapper上注解

        //获取方法上的注解
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        TargetDataSource annotation = method.getAnnotation(TargetDataSource.class);

        //获取类上的注解
        TargetDataSource targetDataSource = method.getDeclaringClass().getAnnotation(TargetDataSource.class);